Project Summary Chronic pain disproportionately affects women, but the majority of preclinical research uses male subjects. Several recent studies show that microglia have a key role in the development of neuropathic pain in male mice, but have no contribution in female mice, where as our preliminary data demonstrate that the pharmacological inhibition of calcitonin gene-related peptide (CGRP) receptors reverses hyperalgesic priming in female mice, but has no effect in male mice. We hypothesize that the mechanisms driving pain plasticity in females rely on a neuronal regulatory program, but a neuro-immune regulatory program drives chronic pain in males. Our research plan proposes to first analyze single-cell RNA sequencing data from male and female mice to independently confirm our preliminary findings and elucidate new targets and/or mechanisms for the development of novel neurotherapeutics for the treatment of chronic pain. We will next confirm that the gene families identified to mediate chronic pain in mice are conserved in human chronic pain patients. We will do this by performing weighted gene co-expression network analysis on existing mouse and human RNA-seq datasets and then perform differential expression analysis on the genes identified in both mice and humans. The work described in this proposal will unveil sex-specific pain plasticity mechanisms that can have an immediate translation impact given the number of anti-CGRPP therapeutics available for use in patient populations. New drug targets will also be identified for pre-clinical validation and development.